"However illegally these documents came to light, they raise serious questions about the reality of America's policy toward Pakistan and Afghanistan."

Just last week, Hillary Clinton said she believes Osama bin Laden is still hidden inside Pakistan.

The documents detail a 2006 meeting with senior Taliban leaders in which Pakistani officials pushed for an attack on Maruf, a district of Kandahar that lies beside the Pakistan border. An offensive began later that year.

The files also link active and retired ISI officers to some of the conflict's most notorious leaders. According to the reports, in 2007, they sent also 1,000 motorbikes for use in suicide attacks.

The reports name former ISI chief General Hamid Gul as a go-between and claim he regularly met al-Qaeda and Taliban commanders to order suicide attacks.

In one classified "threat report", Gul is described ordering magnetic mines to be planted in snow on roads used by military vehicles.

"Gul's final comment to the three individuals was 'make the snow warm in Kabul' basically telling them to set Kabul aflame," the report said.

Another accuses him of meeting Arab "elders" in Pakistan's lawless tribal belt to plan a series of suicide bombings.

Yesterday Gen Gul angrily denied the allegations. "They are talking about a 74-year-old general who retired long ago and has nothing to do with this," he said.

"They are looking for some scapegoat and this is the sign of their defeat in Afghanistan."

Many of the reports are unverified, and Pakistanis have dismissed some of the more spectacular plots as fabrications. One claimed plans to assassinate government officials by disguising a remote-controlled bomb as a Koran, another involved poisoning beer supplies for Western troops in Afghanistan.

Much of the detail came from paid informers or Afghan intelligence officers – regarded as generally hostile to Islamabad.

"Intelligence works in an entirely different fashion," he said. "We receive a preliminary report – which could come from anyone – and then you have to corroborate it from different, independent sources," he said. "A lot of this stuff will turn out to be untrue but we need weeks to check it."